Web roll accelerating apparatus



June 17, 1952 P. L. ToLLlsoN WEB Rom. ACCELERATING APPARATUS 6Sheets-Sheet 1 Filed Jan. 2l, 1949 June 17, 1952 P. l.. 'roLLlsoN WEBROLL ACCELERATING APPARATUS 6 Sheets-Sheet 2 Filed Jan. 2l, 1949INVENTOR PAUL LQ TOLL/50N BY 79M,

ATTORNEYS June 17, 1952 P. l.. ToLLlsoN WEB ROLL ACCELERATING APPARATUS6 Sheets-Sheet 3 Filed Jan. 21, a1949 INVENTOR 'PAUL L. TOLL/50N o BYmuy sMfkmLr/ ATTORN EYS June 17, 1952 P. 1 ToLLlsoN 2,601,071

WEB ROLL ACCELERATING APPARATUS Filed Jan. 21, 1949 6 Sheets-Sheet 4INVENToR PAUL L. TOLLISON June 17, 1952 P. L. To| |soN WEB ROLLACCELERATING APPARATUS 6 Sheets-Sheet 5 Filed Jan. 21, 1949 INVENTORPAUL L TLL A50/V v BY mi ATTORNEYS June 17, 1952 P. rOLLISON WEB ROLLACCELERATING APPARATUS 6 Sheets-Sheet 6 Filed Jan. 21, 1949 ...n wunvATTORNEYS Patented June 17, 1952 UNITED STATES PATENT OFFICE WEB ROLLACCELERATING APPARATUS Paul. L. Tollison, North PlainelcLN. J., assignorto,Wood YNewspaper Machinery Corporation, Plainfield, N. J., acorporation, of Virginia Application January "Z1, 1949, Serial Nio71,896

webscto web consuming apparatus, it is necessary or desirable that aflexible web running from a roll be replaced bya web from afresh rollwhile the Web is running at full operating speed tothe webconsumingrapparatus. Thus, in the supply of paper web to printingpresses, it is customary to employpaper'web rolls and to splice the webfrom a-fresh roll to the `web .running from a depleted roll without.stoppingormaterially retarding the rate of travel of the running web.This roperation has been accomplished by rotatably mounting the Yfreshroll on a movablesupport, such as a web roll reel, accelerating thefresh roll'to a rotative speed or-angular velocity such-that litssurface speed or peripheral Velocity equals `the llinear velocityoftherunning web, thenmoving the fresh ro-ll into Contact l withthe webrunningffrom an `expiring roll to effect a splice betweenY therunningvweb `and the leading'end of the-fresh roll web, and finallysevering the` old web behind the splice. The running web is mai-ntainedunder tension, and to this end, straps, beltsi or like flexible tensionapplying Ymeans are providedI to engage the surface of the roll fromwhich `thevveb runs to the web consumingapparatus andso to retard therotation of such roll. Duringgfresh roll acceleration,` at they time thespliceis made'and for an interval thereafter, the

fresh -roll is either lnot-in a lposition to engage the running tensionAmeans at all or is notv in a position` tovengage thismeans suiiicientlyto prop vide adequate tension.- No tensionis applied from theconventional tension means to the fresh roll While-itisacce1erating,=,andif the speed of the web consuming .apparatus falls atthis time, the new roll web may be moving faster than the runningywebwhenvthe splice is made, which causes an undesirable overrun of theweb. It is accordingly desirable to provide means other than theconventional running web tension means to retard -thelfresh rollrotation until the fresh` roll has been spliced and has thereafter movedto a position where it engages the running web tension means suicientlyto be adequately retarded by such engagement.

It is `preferable that the new roll be accelerated by adriving forceapplied through its axis.Y New rollsareifrequently somewhat non-circularand for -that reason are difficult to drive from means engaging. theircylindrical surfaces. Furthermore, a roll surface engaging drive mayinterfere.

with the adhesive or othersplice-formingmaterial carried at the leadingedge of the new .roll

web. On theother hand, axial drive off-thenew roll involves `regulatingthe rotative speed orl an,- gular velocityrto whichv the roll isacceleratedinaccordance with the diameter `of'- the @articulan roll inuse, since a given vperipheral velocitylis; attained by lower angularvelocity inlarge diameter rolls than in smallones.A In` .practice,-web1rolls vary in diameter to such anextent that there`v rotative speed towhich theyare acceleratedmustf be variedfrom rollito rollito provideaperipheral` velocity that is satisfactoryt foreffecting the: splice toaweb running at a Vpredetermined:speedyA When itis considered that therunning -web speed also varies, and that for satisfactory-splicingthevlinear speedsof the runningweb and gfresh'vrollweb must be.substantially identical, it will bey` appreciated that the problem ofacceleratinggthe new roll to splicing speedthroughaXiaLdrive'is adifficult one.

With the foregoingconsiderations in mindfit' is an object of the presentinvention to provide -f improved means involving axial drive forYrapidly bringingva fresh web roll-up to splicingsp'eed in running web.The invention has yfor-va further object the provision of improved meansfon refA tarding the-rotation ofthe fresh rollv by a force applied`through the roll axis 4both before :the: splice is made if the runningweb speed fallsbe-A low the fresh roll surface speed, and afterth'esplice is made, regardless of web*speedclflanges;`

so as to avoid web overrunning at the time of the splice and to maintaintension on the running web during the interval after the splice when thenew roll is being moved to a position in which: a retarding tensionproducing force is applied a to its surface by conventional running webtension means.-

The above and other objects of the invention; are carried out byemploying an electric motor 5 to drive each fresh roll and accelerate itto speed through itsl axis and vby employing improved mechanism forgoverning the speed to Awhichthe rollffis accelerated 'by the motor.

This is doneY .by providing twogenerators, preferably of thetype knownas tachometer generators, one of which is driven from or at a speedbearing a fixed relation to the speed of the fresh roll, and the otherof which is driven from or at a speed bearing a fixed relation to thespeed of the running web or web consuming apparatus. The operatingenergy applied to the fresh roll driving motor, and, if and whennecessary, a dynamic braking force applied to the fresh roll by thismotor, is controlled in accordance with the relation and differencebetween the roll speed and web speed voltages generated by the twogenerators. According to the invention, the roll speed voltage deliveredby the fresh roll driven generator for comparison with the web speedvoltage is modied by the diameter of the individual fresh roll beingaccelerated. This is preferably accomplished by means of a variableresistance unit, usually in the form of a potentiometer, that ismechanically set by the fresh roll itself to change the fresh roll speedvoltage in direct proportion to changes in diameter of the particularfresh roll being accelerated. This mechanism modifies the roll speedvoltage employed for comparison with the web speed voltage to take intoaccount the particular diameter of fresh roll being accelerated.

The fresh roll and running web speed voltages are compared by anelectronic control circuit that acts to apply operating energy to thefresh roll driving motor when the roll speed voltage is lower than theweb speed voltage, the magnitude of this energy varying directly withthe difference between these voltages. The control mechanism also actslto apply dynamic braking to the roll drive motor if the web speedvoltage drops more than a predetermined small amount below the rollspeed voltage, thus preventing overrun of the web if the web consumingapparatus slows down during fresh roll acceleration or before the spliceis made. Dynamic braking is also applied after the splice is made andduring the interval while the new roll is moved to fully engageconventional running web tension means.

In describing the invention in detail, reference will be made to theaccompanying drawings in which an embodiment thereof has beenillustrated.

In the drawings- Fig. 1 is an end elevation of a web roll reel andassociated mechanism embodying the invention and shown in the positionin which a fresh web roll is accelerated to web speed in preparation fora splice;

Fig. 2 is a front elevation of the mechanism of Fig. 1;

Fig. 3 is an end elevation of the mechanism, viewed from the oppositeend from that shown in Fig. 1;

Fig. 4 is a rear elevation of the fresh roll calipering part of themechanism shown in Fig .1;

Fig. 5 is a sectional view taken along the line 5-5 of Fig. l;

Fig. 6 is an elevation of the web speed generator and a diagrammaticrepresentation of means for driving the same from the web consumingapparatus;

Fig. 7 is a diagrammatic end elevation of a web roll reel showing therunning web tensioning means, with the reel in the position at which asplice is made;

Figs. 8 and 9 are elevations similar to Fig. 7 showing the reelrespectively in the position where the running web tensioning means ispartly effective and in the position in Which such tensioning means iswholly effective to retard a newly-spliced-in web roll; and

Fig. 10 is a diagrammatic illustration of the fresh roll driving motorand its control mechanism and circuits.

In Figs. 1, 2 and 3 there is shown a movable web roll support in theform of a three-arm reel including spaced three-arm spiders and |2carried on and fixed against rotation relative to a central reel shaft I2. The shaft I2' is journalled in bearings carried by brackets I5 and I6secured to columns I'I and I8. The reel may be rotated by a motor I9connecd to the shaft I2 through a gear train 20. Each of the spiders IIand I2 carries roll supporting spindles at the ends of its arms, thespindles of the spider II being designated 2|, 22 and 2'3 and those ofthe spider I2 being designated 24, 25 and 26. The spindles providerotatable supports for the web rolls. Referring to Fig. 1, the rolls maybe designated the running roll R from which the web 28 is running to thepress or other web-consuming apparatus, the fresh roll F that is aboutto be spliced to the running web 28, and a spare roll S that has beenmounted in the reel spindles 23 and 26 to replace an exhausted roll thathas been removed. In Fig. 1, the reel is shown in a position such thatthe fresh roll F is in the speed-up position it occupies while beingaccelerated to running web speed in preparation for a splice. Thespiders II and I2 and the mechanism associated therewith may be mountedfor adjustment axially of the reel shaft I2 for side register, asdescribed in Patent No. 1,957,122.

Means are provided for applying running tension to the running web 28.This means is here shown as a series of straps 3|, one end of each ofwhich is secured to a bracket 32 fixed to the foundation. The other endsof the straps 3| are severally connected to pivoted levers 33 carry ingweight rods 34 with removable weights 35 thereon. As is apparent fromFigs. 1 and 7, the fresh roll F in the speed-up and splicing positionsof the reel is not retarded by the straps 3|. After the splice is made,the reel moves the newly-spliced-in roll F forward and the straps 3|engage increasing arcs of its surface, as shown in Fig. 8, until fullrunning tension is applied by the straps 3| at the running position ofthe reel shown in Fig. 9.

The splice is executed at the proper time by known mechanism such asdescribed in detail in Patent No. 2,148,094. The construction andoperation of such mechanism will be briefly described herein andreference may be made to the noted patent for structural and operatingdetails. The splicing apparatus includes web pressing brushes 36 and webcutting knives 31 pivotally supported on a frame termed the brush arm 33that is pivotally secured at 4E) to the bracket 39 fixed to the columnsI'I and I 8. As shown in Fig. 2, the several brushes 36 and knives 31are disposed so as to be extended into contact with the web betweenadjacent pairs of the tension straps 3|. A brush arm motor 4 I, carriedby the bracket 39, is operatively -connected to the brush arm 38 throughreduction gearing and crank arms so that it lifts and lowers the brusharm under control of the operator. When the running roll R has run olfto the point where the operator considers a roll replacement will soonbe necessary, the reel is turned to the speed-up position shown in Fig.1 and the brush arm 38, which is initially in the position illustratedin Figs. 9 and 10, is lowered by operation of the motor 4I to theoperativeaposition shown .in Figs.;. 1 i and i3. The.I f mol-l E isthen:aeceleratedrftoweb; speed; as; Willbe explained; andathereafter,Wherr `lthe :rune

ning rollRzhassrum off: tothe point where).aispliee;V mustfbe. made, the.-'bnush'esf are extendedfto press..theirunning@Webi=28ifagainstthefresh roll; surface,-. the.--V pastencamyingy leading s end.A of. the`freslfr.y roll` iweb engages fandv'sticks to. .therunning` webandv ith'e1knives 3l iareextendedto sever the oldrWebvbehind-the spl'c'e,=.as.isillustratedsinFig;.7F The brush arm-38 then raised andfat thefsame..time the :ireel is turned-f-Lforward; that r is, in the; direction-offthe-arrow. .inf 1, to.:progressively move the newly-spliced-in roll F'to itsarunningf position-,as :illustratedin Figs. Siand- 9.?.It'wvill'be understoodth'at known .mechanismnis employed tof effectandlcontrol the 4described i coordinated. movements of tliefz-brushfarm,-the-brushes, the. knives and the-reel. Suitable mechanism of .this

nature-is" shown-1in: Pater-1t 'No; 2 ,148 5094,; referred: 'P

tov-above.t The-freshf roll"V accelerating..y and Preetarding'mechanisnr of the present invention is preferably=.coordinatedf@Withethe @splicing-K opera-- tionfby contactscontrolled-.by the-position of `the: brush-farmI 38; as will bedescribed.

An eleetric'emotor-42 'is providedffor- `accelerat` ing@ each successivefresh-Webhroll toerunningc web speed "and forretardi'ngthe rotati'orr'ofsuch roll, as will be explainedv The motor-152isshovvnfAmountedfoneabracketi lfixed"to`-a-cross beam 44-'- (Figs- 2 wand# 3) Itis-conneeted-y to drive a cross "shaft LEM-through suitable means;suchas thesprocketsf Mfand thechain-d3;-` A roll*l speedtachometergenerator 49 A'is' Amounted on-the bracket 43 and isdirectly-connectedtothe motor 42 by-a' suitable means; such-,as thesprockets 53 and 5 l' and-the chain* 52, so that this-l generator yrotates -at ai'speed and accordingly' generates -a= Vol'tage bearing? afixed `relation-:to the angular velocity-or-rotative speedat whichthefresh roll turns Rol-l driving power istransmitted'to {each-'freshl rolfAin turnbyfmechanisnr -nowfto bodescribedr The shaft"451is connected'bybevel' gearsy V53 to ae vertical shaft' '54|4 journalled-infthe banjoiframe 55;A The g'b'anjo 'frame 55 `is stationary;- andethe'V reelspider 1| 2 includingthe vspindle clutchr housings 55j; turnsV withY theAreef shaft Ai2 relative thereto;- Roll drivingpower vfrom-the shaftl5ft-" is .transmittedthroughthe rbevel gears-5i and` ga" stubshaf,t"58^to a; pinion '59." Theitainicvne)'eneV gages'a gearxed toalargegeary 6I concentrc.,therewith' and rotatably journal'led on-"thehubiof the spider l2: The-large geari engagesI three spindle driveigears62mountedrespectively on the shaftslof the three spindles 2i; 22 'an-d23,3 Each of Athegears 62 iis operativelyvconnected -tol its spindleshaft by a clutchincludingatoothedi element 'V64 'fixed to thegearfandacomplee mentary movable toothed element 65-splined jto but slidablevalongg-the .spindleshaftrl A'pivotally mounted yoke 'jengages acircumferential slot' in the movable clutch el-ementand isnormallybiased toa `clutch engaging positionpy a spring T0 'connectedbetween anarm 61 ongthe yoke vpivot shaft 68 and the spindle journalhousing E9 V(Figs. 2.and 3). Thelower end .of the lever formingthejmlfle.1 Scarries a. roller 1 I,that jis engagedand.disengagedmyacam. .T2 .xed tothe station-4v arybanjoframe.asthespiderfi turns.. This... action of `the, cam` 12...engage-s and. disengages i the l.

clutch; .elementi 65 I.from 'the clutch .elementAsshovvnin.Fig.2;sthe.camfi2 hasa gap thereinw extendingfonabout1100?-to: reel rotation; start-i Y ingfat afpoint 'just` before eachl spiderarmreaches f its. @upper ver-tical, position Vand f, continuing: f to.1a.. point just above the.-.horizontal position ofxthe spider armadjacenttherunningweb: Withzthis.

. arrangement,4 the fclutchff elements .613 .i and` :55 of each spindleareengagedzito operatively connectthespindle and thustheweb roll carried`thereby 1 to the roll driving .motor ,42,v as .thespindle apiproachesthe roll' speedu-p.` position Ain `whichthe.

, spindle `25 :isxshown in Fig; 3;. The clutch ele-.-4

ments are disengaged; when thev spindle appreaches therunning.:position. .illustrated .bylthe roll .FinsFig .9.. Thespindledrive andiclutchmechanism hereiny described .is disclosed inmoreV idetail in Patent No. 2,148,094;

In. accordance. with-the present invention the roll.v speedivoltagegenerated, by f the.v generatorA 49 is` modified `in iaccordance With:the: diameter of each fresh roll thatfisaccelerated :to splicing.`

The fresh roll 1 calipering: and4 associated :mechanism employedifor.-this. purpose is shovvrrin Figs'. l,.4.';and5; A'roll measuringlarm 'i3is `fpivotally .supported above the spider. l2 .by c suitable means,such'asa bracketfi;v A 'rollerliil at'thefree end-fof the armIsis-disposed. to.. be engaged. by .-the'. periphery ofa freshfwebarollaszit moves .toward 'theaspeedeup position .(Figs.. ran-dill); Thearm.13jcarries a ratcheti.. The `ratchet yl5? is. normally engagedfbyaspring.. pressed fpaWl TS pivotallyI connected to. a .fixed frame?? by ashaft295.' The pawl'lisconnected by anarm '.31to abell crank'lever 19,thexlovverv armgof-'which carriesfa. rollerl disposed inV the.` pathcf.projections 1.8i, one` of whiclr-is fiXedlon. the spindle journalled:housing 69 :of each Varm' ofthe reelspider i 2.. A'spring v821biasesthe pawly lef. andszits operating: mechanism toward the ratchetfengaging@ position.:

A=.rack.83',. xede'to move with-thefarm 732i througha'rack armlifandthepivot shaft-311:0? theyarm '13; engagesfapinionid '..carriedLbystublshaft 85 :,journalled` :in: the frame 1T' (Figs. la1id15) The shaft85i1carries appinion 8Eijerr gaging. a gear 'lrlxed to the-movable:contact operating. shaft 88 =:of a :potentiometer .-83 .that .1s carriedin ra -housingllfxed v.to.thefframew'il; as shown; in Figs.: 4 and 5.:The.A potentiometer Vis electrically l connectedgfto the Youtput;circuitof the roll speed voltagefgenerator 49; as Wil'lbexde-Jv scribed.;

With the describedarrangement, as geachrarrn.v of-f the )spider i2-approaches yits upper'. verticali position and the iwebt roll'- carriedby-fthe.v spindle f on; such varm is adisposedgbeneath.:the roller: 15'?.onizthe measuringwarmen; the vproj ection -8 lv er1-- gages f theroller r 33and.;lifts ntheflower.- arm. of the .-bellicranklever.19,fathus .disengagingthe pawl E' Gafrom the ,ratchet `I5 'f`anclzpermitting the arm 'Sto descend "until itiisarrestedibynengagement: oirits; roller V'l 5 twithfthe surfacefofjthelfweburollp As. the reel advances, the peripheralsurface of the 1webrollfliftsthefarm J3 .to-atpositiorrfcorresponde ingltoVthe-.diameteriof thai-oli, andfeth'e farm, is heidrin .thisposition-byengagementfof thepawl 'igfgwitliathe .ratohet T554.V Themovement. of .the-

:istransmitted-to the sh'aftzeof fthe potentiemeer f8 il yandethe.potentiometer i is :.:thus set tesa.f position ,correspending;V to-xthediameter. @of thefffresh-.roll ;that-:is:beingmoved;to-.;the -rollspeede-,upiposition Tr uri-ning webpspeed v1voltage-senerator 9 lgis-drivenefrom the-zwebfconsuminggapparatus at= a. speedgbearingg; awxed relations to. thexspeed of the running;` fvveb, wherebytheevoltag@gene crates-.5;i varies f directly.; within: the-1 runrinsiz, websspeed. As illustrated in Fig. 6, the generator is connected by suitablemeans, such as the sprockets 92 and 93 and a chain 94, to a shaft 95that drives the web-consuming apparatus, in the i1- lustrated case, aprinting press indicated by the printing unit PC. As is illustrated inFig. 6, the shaft 95 drives the unit PC through the bevel gears 96 and91, the shaft 98 and the shaft of one of the impression cylinders I ofthe printing unit that is represented by the plate cylinders P, P andthe impression cylinders II. These cylinders directly engage the runningweb 28 and accordingly the speed at which the generator 9| is drivenbears a direct relation to the linear speed of the running web.

The apparatus for applying and controlling the operating energy for thefresh roll driving motor 42 and the dynamic braking of this motor toretard fresh roll rotation will now be described. This apparatus isillustrated in Fig. 10.

The roll drive motor 42 is a compound wound direct current motor havingan armature A, a shunt ileld SF and a series field EF. Energy foroperating this motor is derived from an alternating current power sourceAC through a rectifier employing grid controlled gas filled tubes of thetype known as Thyratrons, two of which are illustrated at |00 and 20|.By employing rectifier tubes of this type and an electronic controlcircuit which governs the firing of these tubes, the amount of energysupplied to the motor 42 may be very rapidly varied and accuratelyrcontrolled. The rectifier power supply does not, however, permit dynamicbraking of the motor by merely decreasing the potential of the supplybelow the potential generated by the motor when it is driven by themomentum of the rotating fresh web roll and this for the reason that arectifier conducts electric current in one direction only. For thisreason, the mechanism is arranged to connect a dynamic braking resistorI I6 across the motor armature A and series field EF to provide dynamicbraking or retardation of the motor and thus retardation of the rotationof the fresh web roll when required. In general, the electronic controlcircuit compares the fresh roll speed voltage generated by the generator49 to the running web speed Voltage generated by the generator 9| andsupplies operating energy or applies dynamic braking to the roll drivemotor 42 in accordance with the relation and relative magnitude of theseVoltages. More specifically, the circuit acts to supply operating energyto the roll drive motor 42 in an amount directly proportional to thedifference between the roll speed voltage and the web speed voltage whenthe relative value of these voltages indicates that the fresh roll speedis less than the running web speed, and to apply dynamic braking to themotor when the relative value of these voltages indicates that the freshroll speed exceeds the running web speed by more than an exceeding smallpercentage.

As has been explained, the fresh roll speed voltage employed forcomparison with the running web speed voltage is modified in accordancewith the diameter of the particular web roll being accelerated. As shownin Fig. 10, the resistor |02 of the roll diameter responsive potentiometer 89 is connected across the terminals of the roll speed generator49, and the movable arm |03 of this potentiometer, which is moved by theshaft 88 as has been explained, is raised to increase the proportion ofthe generated voltage delivered to the output circuit in comparison withthe web speed voltage as the fresh roll diameter increases and islowered to decrease the proportion of such voltage so delivered as thediameter of the fresh roll decreases. Thus, with a relatively largediameter fresh roll, the roll speed voltage employed for comparison ishigher for a given angular velocity of roll rotation than With arelatively small diameter fresh roll. The roll speed voltage employedfor comparison is thus modied directly with the fresh roll diameter toindicate the peripheral velocity of each fresh roll that is to beaccelerated, despite diiferences in diameter between the individualrolls.

Referring to Fig. 10, alternating current from the source AC is suppliedto the primary winding I 05 of a power transformer PT through a switch|04. The switch |04 is connected to operate in unison with a fieldcontrol switch |06 which supplies direct current from a source DC to atime delay relay TR, the contacts II2 of which are connected in theshunt eld current supply circuit, as will be described. The relay TR isof the delayed closing type and its contacts II2 do not close until apredetermined time interval has elapsed, following its energization.This permits the various tubes of the circuit to warm up to operatingcathode temperatures before the shunt eld circuit is closed.

The secondary winding |01 of the power transformer PT supplies energy tothe circuits of the rectier tubes |00 and 20| and these anode circuitsinclude in their common cathode return circuit |08 the series field EFand the armature A of the roll drive motor 42. This circuit iscontrolled by a main contactor M, the front contacts |09 of which areincluded in the common cathode return circuit, as shown. The shunt eldSF of the motor is energized from a rectifier comprising the tubes I|0and I|I, energized from the power transformer secondary winding |01through a circuit including the contacts II2 of the relay TR., the coilII3 of a field loss relay FLR and a variable resistor II4. The variableresistor I I4 is operatively connected to and varied by the movement ofthe brush arm 38, and is arranged to be completely cut out of the fieldcircuit when the brush arm is in its lowered operative position as shownin broken lines in Fig. 10, and to be completely cut in that circuitwhen the brush arm is in its fully raised inoperative position. Thefront contacts II5 of the main contactor M shunt out the variableresistor II4 when the main contactor is closed. The dynamic brakingresistor I I9 is connected across the armature A and series eld EF ofthe motor 42 when the dynamic braking relay DBR is energized. The coilII'I of the dynamic braking relay may be energized through a circuitincluding the back contacts- II8 of the main contactor M so that dynamicbraking is applied and is controlled by the position of the brush arm 38when the main contactor M is deenergized and so opened. To simplify thedrawing, the energy for the dynamic braking relay circuit and for othercontrol circuits has been indicated by plus and minus signs.

The brush arm drive motor 4I is energized from a source indicated at L1,L2 under the control of a raise contactor |29 and a lower contactor I2I.When the raise contactor |20 is energized, the motor 4I is energized tooperate in a direction that raises the brush arm 38 through a circuitincluding the front contact |22 of the raise contactor, the back contact|23 of. the. lower contactor .I2 Luand .the :motor eld .|24. When thelower contactor l2 |J is energized, Athe motor 4| is energized `tooperateinasfdirection `to lower .thebrush .armii through.;a circuitiincluding the `front contact` |25. of .the lower contactor, the .backcontact; 2 2 foi '..Lthe .raise contactor, `and .the motor. eld. |26.The raise and lower contactors maybe :energizediin any s known. manner,as,..for example, by .the .mechanism disclosed .in the.. aforesaid.PatentaNo. 2,148,094. To simplify Athe present .disclosure, thereisshown a .raise switch, |21. for. .energizing the.. raisecontactor |20.anda lower.A switchfl28 `for. energizing the .lowercontactor |21, the-circuits controlled by these switches beingapparent f l from thedrawing.

The operatingy coil |29 or"..thefmain;contactor energized by .a .circuitincluding fthe back contact |30 of the raisecontactor .|2U,..-the frontcontacts |`3| of the ii'eld loss relay FLRand the contacts 320i thebrush arm operatedcontactor C. The contactorC is` operated `@byfacam-|33 `connected tobe turnedbymovement ofthe brush arm |33 and arrangedtoclose the contacts |32 .in

all brush arm positions except-its fully raised -inl operative position.rIhus, the main COntactOr-flVI .isv energized to supply .Operatingenergytothe roll drive motor 42when the brusharm; 38 is moved down from itsinoperative Vposition and isthereafter vnormally maintainedvenergizeduntilthe brush arm is fully raised'after avspliceis made and the newlyspliced rollfis. advanced by the reel to running position.

In the eventthat the shunt neldSFoi thelmotor 42 is deenerg-ized foranyreason, as, -ior example, byrfailure ofone or bothpfthe. rectifier tubeslill and |,the iield loss 'relay-winding H3 is deenergized and thecontacts |'3| of-this relay open, thereby breaking the main contactorenergizing circuit; disconnecting theyroll drive,motor 42 from itssource of operating energyand-ap plying dynamic braking to thisxmotor.

.The amount of operating energy supplied to the roll drivemotor 42 bythev rectii-ler tubes Ille and 20| is controlledby an electronic`control'circuit responsive -to the difference .between ywebspeedvoltage and the fresh-roll .speed voltageas modi- 'ed by the fresh rolldiameter. `A centertapped secondary winding |34 of thelpower transformerPT -is connected in a phaseshiftingbridge lcircuit thatcontrols theyphase relationfbetween the-grid potential andthe cathodepotential`ofthe Vrectifier tubes |00 and 20| and so governs the ring and theaverage current supplied `by `these tubes. One leg of this-bridgecircuit .runs -from fthecenter -tap .of the secondary winding |34through-the primary-winding |35 of ar gridtransformer GT andto. thecommon wire |36. 'I-hesecondary windings ofthe grid transformer GTv arerespectively .connected in thev gridcircuits of-vthe tubes 4HJ() l and20L. as shown. AH second leg ofthe bridge circuit runsl .from one endoffthetransformer secondary .winding 34 through .a resistor|'3|..to.the. common Wire |36. `The .third'leg of the bridge circuitruns .fromthe opposite endof the transformer secondary winding |34through the wire` |38 in parallel 'through the twoal-ternating currentwindings |'39and' |40 of the saturable core reactor-SC'to the commonlwire |36.

The saturable corereactor SC carries a direct current winding|4|-connected inthe` anode circuitof a grid controlledfvacuum'tube D.`vvThe described -bridge circuit acts in. a' known manner in response':to L an increase .ingthez current rinthe winding I4 V of the satur'ablecore reactor toqcause the recterftubesl |l;.20 I. .to ure-or .conductcurrent earlier in thecycle ofv thealternating current. .impressed on-their anode circuits and .thus .to .pass .alarger average. anodecurrent. and soincrease theoperating energy suppliedto the. arma- .tureA-A and series ield'EFof the roll drivexmotor 42. '.Aidecrease/incurrent through .thewinding =|4 of Lthesaturable `core reactorsimilarlycauses `a smalleraverage currentto. be supplied..to...the lmotorili. bythe rectifier .tubes il?) and 20| "Thus, the amount. of. operatingenergy supplied to .the roll.v drive..motor .is varieddirectly .with.changes .in theanode current of thetube D.

.Energy .for operating. .the tubeD and .theother control tubes. to.bedescribed is .derived fromthe rectifierincludingthegtubes and|||.,through the wire. |142. LJByymeansof theseries connected voltageregula-tor tubesVGandVB; the Wire 1.42 yisheld at a steady positivepotential .with respect .tothe negativeor return wire |43. that leads tothe .center .tap .of the transformer secondary .winding |01; fromwhich-the rectifier tubes H0 and lllV are energized. -A wire |44 isconnected betweenA the `two voltage regulator tubes VG and VB andso.is;held;ata positive potential approximately. half lthat maintainedon the wire |42.

The anode circuit of the tube D runs from the anode of ,that tubeto thedirect current winding |4| of. the saturable-core reactor SC to the wire|42, and from the cathode of the tube D to the .wire |44. The ,gridfoithe tube D is connectedfto anfintermediate point in a voltage dividingresistor vcircuit, extending between the wires |42 and |43 andincludingthe resistors R2,R3, R.|| andR5. The potential applied -to the grid of.-the .tube D -is varied by a grid controlled vacuum tube V, the gridand-cathode potentials of whichvare .respectivelyvaried-in accordancewith changes in running. web yspeed voltage and `fresh roll speedvoltage; as will now be explained.

VThe anode of the tube V is connected through the wires |45 and A|453 toapoint between the resistorsMR2 and R3. The cathode of this tube isconnected through the wire 2i) to the-moving contact-oa `potentiometerRl, the resistor of which uis.- connectedin series with the terminals ofthe running-web speed generator 9 I. A variable resistor-|41 is includedin this series circuit. The cathode circuit of the tube V is connectedto the negative return-wire |43 through a variable resistor R6, which.provides adjustable negative gridf-bias for the -tube V. The gridcircuit of the tubefV is completed through the return wire |43;alresistor RID, the resistor and the movable contactof apotentiometer R4and the wire |48. Aggrid-condenser |89 `is connected between the gridandthe cathode of the tube V. The resistor ofthe potentiometer`R4 is.connected to receive current, proportional to the voltage generated bythe .fresh roll speed generator 49 asmodied bythe -fresh :roll diameterresponsive .potentiometere89. `To this end, the resistor ofpotentiometer-R4 is; connected through the resistor R9to1the"movable;"arm |63 of the potentiometer 89, .andthe. resistor ofthe potentiometer A8S Yis connected .'in. series with the vfresh. rollspeed generatorfdlxfthrough the wires |49, leef-15| and. 43.

'.iTheV tubeHVis .ofxthe sharp cut-ofi vtype and the; constants; of.;the" described circuits Aof Vthis tube-fare: so chosen` vthat-when theperipheral velocity: .of the -fresh roll, as determined by .theterminaliV voltageof theygenerator-dg modified Icy-fthe:V roll diameter:responsiveV potentiometer 8,9,'-matches-the running web speed asdetermined by the generator 9|, the grid of the tube V will be biasednegative with respect to its cathode to an extent that the tube willoperate on the steep portion of its characteristic curve, and will passjust enough anode circuit current to fix the bias of the grid of thetube D at a point where the anode current of that tube will cause thepower rectifier tubes and 20| to supply just sufficient energy to theroll drive motor 42 to drive the fresh roll at'the matched speed againstthe friction and windage load thereon. When the fresh roll speed isbelow the matched speed condition described, the grid of the tube V isat a lower potential with respect to its cathode than that obtainingunder matched speed conditions and the tube V becomes non-conducting,thereby raising the potential on the grid of the tube D so that anincreased amount of energy is supplied to the roll drive motor 42. Thedescribed circuit thus operates to supply to the roll drive motor 42 anamount of energy directly proportional to the excess of web speedvoltage over roll speed voltage as modified by fresh roll diameter. Withthis arrangement, each fresh roll is accelerated to an angular velocityor rotative speed such that its peripheral velocity is equal to that ofthe running web, and is held at such speed until the splice is made.

When the fresh roll is at a standstill or is turning slowly, its inertiaimposes a heavy load on the motor 42, and means are provided to limitthe current drawn by this motor under such conditions and so to protectthe motor and the rectifier tubes |00 and 20| against damage or failuredue to overload. A rectifier tube FF is supplied with alternatingcurrent by a transformer IT having primary windings |56 and |51connected, respectively, in the anode circuits of power supply rectifiertubes |00 and 20|. The

secondary Winding |58 of the transformer IT has a center tap connectedto the negative return wire |43 through the resistor |59. The cathode ofthe rectifier tube FF is connected through the resistor of apotentiometer IVR and the xed resistor |00 to the negative return wire|43. With this arrangement, a direct current voltage proportional to thearmature current of the motor 42 is produced across the resistor of thepotentiometer IVR. A predetermined part of this potential is impressedon the control grid of a current limit tube DD, the anode of which isconnected to the wire |45 and the cathode of which is connected to thewire |44. The cathode potential of the tube DD is held by the voltageregulator tubes VG and VB at a value considerably more positive than thenegative return wire |43.' The value of the fixed resistor |60 and thesetting of the potentiometer IVR are so chosen that the grid of the tubeDD is biased negative with respect to its cathode to an extent that thetube is non-conductive for all values of armature current in the motor42 below a predetermined maximum safe value. If the motor armaturecurrent exceeds the safe maximum value, the potential on the grid of thetube DD rises to and past the cut-off point, and the tube DD, which hasa sharp cut-off, becomes conductive, drawing current through theresistor R2 and so drawing the grid of the tube D negative and phasingback the firing point of the rectifier tubes |00 and 20|, thus reducingthe armature current supplied by these tubes to the motor armaturecircuit to a safe value. It sometimes happens that the speed of thepress or other web consuming apparatus drops while a fresh 12 roll isbeing accelerated or after the roll has been brought to web speed butbefore the splice is made. This, of course, results in a drop in runningweb speed. If the running web speed thus decreases to a value that isabove the peripheral Velocity of the fresh roll, the result of thedecrease is merely to lower the potential of the cathode of the tube V,and so lower the fresh roll speed at which matched speed conditionsobtain, as described above. If the running web speed falls appreciablybelow the peripheral velocity of the fresh roll, due to a considerabledrop in web speed during fresh roll acceleration or to an appreciabledrop in webspeed after the fresh roll has reached matched speed. it isadvisable to retard the rotation of the fresh roll so that no overrun ofthe web can result when the splice is made. Retarding of the fresh rollunder these circumstances is accomplished under control of the tube Vthrough a tube CC, the anode circuit of which is connected to the wire|42 through the winding |52 of a relay DR. The cathode of the tube CC isconnected to the wire |44 and its grid is connected between the seriesconnected resistors R3 and R| The back contacts |53 of the relay DR. areconnected in a circuit including the wire |54 that energizes the dynamicbraking relay DBR and so connects the dynamic braking resistor ||6across the armature A and series field EF of the motor 42 when themovable contact |55 of the relay DR drops. A sudden drop in running webspeed to a value appreciably below the peripheral velocity of the freshroll draws the cathode of the tube V so far negative with respect to itsgrid that the tube operates well above its cut-off point, drawing fullanode current through the wires |45 and |46 and thus drawing the grid ofthe tube CC so far negative that the relay DR drops its movable contact|55, thus applying dynamic braking to the roll drive motor. As soon asthe speed of the fresh roll drops to a value such that its peripheralvelocity substantially equals that of the running web, the cathode togrid potential of the tube V is reduced to the point where the anodecircuit current of this tube drops, thus permitting the grid of the tubeCC to become more positive, with the result that the winding |52 of therelay DR receives sufficient energy to lift the movable contact |55,thus deenergizing the dynamic braking relay DBR and discontinuingdynamic braking of the fresh roll.

The constants of the described circuits are so chosen that a decrease inrunning web speed to a value only slightly (i. e., about one-half of onepercent) below the peripheral velocity of the fresh web roll does notalter the cathode to grid potential of the tube V sufficiently tooperate this tube above the steep portion of this characteristic curve,and thus does not result in sufficient current in the anode circuit ofthe tube V to cause dynamic braking, as described. In such a case, theresult of the drop in running web speed is merely to reduce the amountof operating energy supplied to the fresh roll drive motor 42 by drawingthe potential of the grid of the tube D slightly more negative than itwas at the matched speed condition. As the operating energy for themotor 42 is thus slightly reduced, the friction load on the motor, thefresh roll and the driving connection therebetween, is sufficient topromptly reduce the roll speed to a value that matches the web speed,and the 13 .-'cathode :potential `of the tube i V is thereby? so reducedrelative to its gridpotential thatenergy lstiflicient l to maintaink thefresh roll at the matched, speedV is supplied to the roll drive"motor:42.

. The. operationof the disclosed' mechanismwill `new -beexplained 'Some'time during the run- `ningfor `of the web from therunning rollR,the'operatoradvances the reel to place the fresh rollFi-in thespeed-upposition shown inF-igs `l--`and3. The powerswitches'lll and lareclosed-at orprior to this time'and havere- `Inainedclosed-l forasuflicient interval tovpermit heating offthe` cathodes of `the,rectiiier' tubes IGU,L12I,Y U01-and lllV to operating temperature. VTherelayTR has accordingly closed its' contacts H2. A'As' the fresh rollFmoves to the vspeed--up position, the roll size potentiometer: 88 isset Aby '-thelfresh rolLF, as hasbeen'explained, to a position inWhich-vit modies the voltage genertated by the roll speed generator'lgso as' to pro duce-at the grid of the 'tubeV a voltage correirspend-ingto the peripheral velocity oflthe particular` ffresh roll. Alsoduring-advancing of the roll l to -speed-upposition; the clutch llgothefr-esh roll spindle 22 is engaged byfmovement fofthe roller 'H offthecam 72,*and in-'thislmannerlthe motorW-"QZ andthe roll-speed'generator "49" are operatively connected `toV the fresh roll'F.

f-"When'from the* size of the depleted-running -ro'll -R'lthef operatorjudgesv that a` roll replacement is necessary, he lowers the brush arm`33 f-to itsf-vertical operating-positionfas shown in Figs.1,` 3 and 7,by closing' the lower switch 4728. i'llhe initial vdownward movementv'ofthel brush armv from its raised 'inoperative position-closes the-contactor C. This'energizes-andV closes the main-contacter M through aAcircuit including thecontacts |32 of the contacter C, the-contacts l3lof the field loss relay FLR- and the back contactl3-of the raisecontacter-126. -Closureof the main contacter-M applies'operating energyfrom the rectifier tubes 100 and 29 l-to the arma- `-ture and series eldcircuit of the `roll -drive motor42, which then starts'and accelerates-the fresh roll. TheV amount vof energy supplied to the motor =42 isreduced in proportion to the reduction of the Vamount by which therunning 'Web-speed Voltage ofthe-generator 9| exceeds the roll speedVoltage of the generator 4! as modified by the roll sizepotentiometer'yand "whenthese voltages are'matched, which occurs whenthe peripheral velocity of the fresh roll matches the linear velocity ofthe running web 28, Vthe'amount of operating energy supplied to themotor 42 is just enough to maintain roll rotation at the matched speed.

`If during acceleration or prior to splicing, the `presser other webconsuming apparatus slows 4down enough to bring VVthe web speed morethan `about-one percent below the peripheral Velocity `ofthe Yfreshroll, the relay DR drops its contact `l55^and energizes the dynamicbraking relay ljR-"thus connecting the resistor across the motorarmature A and series `field EF to apply dynamic braking and retard thefresh roll `speed tof a value at which its peripheral'velocity again-matches the speed of the running web. When the fresh roll has thus beenretarded to matched speed; the relay DR lifts its contact |55,deenergizes'the dynamic braking relay DBR and so dis- #connects'the'resistor H6 from the motorarmat'ure circuit.

After the spliceis made, the brush arm 38 is '-raisediby closing of theraise' switch 121,.ar-id at 14 'Ithe samev time' the reellisadvancedlprogressively -througli'l'thelposition shown ini-Fig' tof-therunning positionfshown in Fig.9. The raisefswit'ch maybe-closed andf thereeladvanced byautomatic mechanism -initiated byv =the-`operation` oftheknives T37 'atlthef conclusion ofthe splicing operation, as``is"diselosed`in` lPatent No; 2,148,094. 'To simplifythepresentdisclosure such automatic mechanism-isnot shown. Energization--of'ftheraise contacter 26 opens the energizing circuit for the main contacter-Mand soldisconnects operating energyfrom themetoriarmature A and seriesfield "EFL Deenergization-` ofy the 'main contaetor' yM- alsoenergizestheI dynamic ybraking relay DBR- 'through the back `contacts H8'and opensv the shunt, including the; vfront contacts 5,f around ftheibrush arm operated' variable resistor H4. -Dynamic brakingthus-applied-'to lretard. the newly-'spliced-in rolliinmediately afterthe' splice is made and before the' -rollY -is-mloved into contactwith'the tension straps3l. "As-the newroll'F- moves progressively -intogreater peripheral ycontacty with the straps' 3 l the value -of thevariable resistor H4 is increased "by-upward -movement `of the brush'arm38, thus yreducing the shunteld current andftheldynamic braking4retardation ofthe neWly-sp'liced-in roll. When the" brush-'arm'lS-Syreaches itsully raised inoperative position, ythe contactor'C'isropened bythe `cam R33 `and th'is maintains `the maincontactor M A`deenergi'zedy despite the -factthatthe? raise lcontacter liis thendeener'giZed-due to opening 'of the raise switchv 12T-by 'the operator.Atfthe running -positionofthe* reel,-the` clutch of -the i' freshrollspindle is'`disengaged"byf movement of the -roller 'i lontothe cam''12.

1.-"Web Aroll Aaccelerating apparatus comprising the'vcombination-withweb consuming-apparatus and' aiweo `running thereto; of; awebrollsupp'oit, an-electricmotor connectedwtodrive a; rlllon said ysupportlthrough its axis; a -runningwebspeed generator `driven frornsaidwebconsuming- 'apsaid' roll speed generator directly with #and "iinproportion' to the initial diameter "of afresh* rll on said support, andmeansfrespon'sive-to the relation'between the voltage generated bysaidweb speed 'generator and 'theov'oltage -geneltediby said roll speedgenerator as reduced" by said-voltage reducingmeans for governing theamount-fof energy supplied to'saidA motor.

ZJ'Web roll accelerating apparatus comprising 'the combination withwebconsuming apparatus and a" web 'running thereto, of a webv rolllsupport, an electric motor connected to drivea-roll on saidsupportthrough its axis, arunningiweb speed generator driven from-saidweb 'consuming apparatus at a speed proportional to the 'speed of travelof said running web, a fresh roll'speed generator' driven from saidmotor at a speed proportional to-the angular Velocity of a roll on saidsupport, means for `supplying operating energy ofV variablemagnitudevto-said motor-, meansfor variably reducing the voltagegenerated by said `roll-speedgenerator, Ymovable means responsiveto"the.diameterv of -a Afresh-web rollon said support :forAsettingfsaid'- voltage' 'reducingsmeans to reduce the roll speedgenerator voltage directly with and in proportion to the diameter of afresh web roll on said support, and control means responsive to theamount by which the voltage generated by said web speed generatorexceeds the voltage generated by said roll speed generator as reduced bysaid voltage reducing means for supplying to said moto;` from saidenergy supply means an amount of energy proportional to such excess.

3. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a web roll support, anelectric motor having an armature and a series field connected to drivea roll on said support through its axis, a running web speed generatordriven from said web consuming apparatus at a speed proportional to thespeed of travel of said running web, a fresh roll speed generator drivenfrom said motor at a speed proportional to the angular velocity of aroll on said support, means for supplying operating energy of variablemagnitude to said motor, means responsive to the amount by which thevoltage generated by said web speed generator exceeds the voltagegenerated by said roll speed generator for supplying to said motor fromsaid energy supply means an amount of energy proportional to suchexcess, a resistor, and means responsive to an excess of roll speedgenerator voltage over web speed generator voltage for electricallyconnecting said resistor in series with the armature and series field ofsaid motor to apply dynamic braking to a web roll driven by said motor.

4. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a web roll support, anelectric motor having an armature and a series eld connected to drive aroll on said support through its axis, a running web speed generatordriven from said web consuming apparatus at a speed proportional to thespeed of travel of said running web, a fresh roll speed generator drivenfrom said motor at a speed proportional to the angular velocity of aroll on said support, means for supplying operating energy of variablemagnitude to said motor, means for variably reducing the voltagegenerated by said roll speed generator, movable means responsive to thediameter of a fresh web roll on said support for setting said voltagereducing means to reduce the roll speed generator voltage directly withand in proportion to the diameter of a fresh roll on said support, meansresponsive tothe amount by which the voltage generated by said web speedgenerator exceeds the voltage generated by said roll speed generator asreduced by said voltage reducing means for supplying to said motor fromsaid energy supply means an amount of energy proportional to suchexcess, a resistor, and means responsive to an excess of roll speedgenerator voltage over web speed generator voltage for electricallyconnecting said resistor in series with the armature and series eld ofsaid motor to apply dynamic braking to a roll driven by said motor.

5. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a webl running thereto, of a movable fresh rollsupport, an electric motor connected to drive a roll on said supportthrough the axis of such roll, a running web speed generator driven bysaid web consuming apparatus at a speed proportional to the linearvelocity of said running web, a roll speed generator driven by saidmotor at a speed proportional to the angular velocity of a fresh roll onsaid support, a potentiometer connected across the output circuit ofsaid roll speed generator, a movable arm connected to operate saidpotentiometer having a part thereof disposed in the path of movement ofthe peripheral surface of a roll on said movable support whereby saidarm is moved and said potentiometer is set by movement of a fresh rollon said support to reduce the voltage generated by said roll speedgenerator directly with and in proportion to the diameter of such roll,and means governed by the voltages generated by said generators forsupplying to said motor an amount of operating energy proportional tothe amount by which the voltage generated by said web speed generatorexceeds the voltage generated by said roll speed generator as reduced bysaid potentiometer.

6. Web roll accelerating apparatus comprising the combination With Webconsuming apparatus and a web running thereto, of a fresh web rollsupport, an electric motor having an armature and a series fieldconnected to drive a roll on said support, web speed responsive meansdriven Y by said web consuming apparatus, roll speed responsive meansdriven by said motor, a resistor, and means responsive to an excess ofthe roll speed indicated by said roll speed responsive means over theweb speed indicated by said web speed responsive means for connectingsaid resistor in series with the armature and series field of saidmotor.

'7. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a fresh web rollsupport, an electric motor having an armature and a series fieldconnected to drive a roll on said support, Web speed responsive meansdriven by said web consuming apparatus, roll speed responsive meansdriven by said motor, means responsive to an excess of the web speedindicated by said web speed responsive means over the roll speedindicated by said roll speed responsive means for supplying operatingenergy to said motor, a resistor, and means responsive to an excess ofthe roll speed indicated by said roll speed responsive means over theweb speed indicated by said Web speed responsive means for connectingsaid resistor in series with the armature l and series eld of saidmotor.

8. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a fresh web rollsupport, an electric motor connected to drive a roll on said supportthrough the roll axis, a

web speed responsive generator driven by said web consuming apparatus, aroll speed responsive generator driven by said motor, means for variablyreducing the voltage generated by said roll speed generator, meansresponsive to an excess of web speed generator voltage over roll speedgenerator votage as reduced by said voltage reducing means for supplyingto said motor an amount of operating energy proportional to such excess,

' and roll calipering mechanism responsive to the diameter of a roll onsaid support for setting said variable voltage reducing means to reducethe rool speed generator voltage in direct proportion to the diameter ofthe roll.

9. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a web roll reelrotatable to move a fresh web roll to a position in which it isaccelerated in preparation for splicing its web to the running web, anelectric motor connected to drive a roll on said reel through the rollaxis, a running web speed generator driven by said web consumingapparatus at a speed proportional to the linear velocity of the runningWeb, a roll speed generator driven by said motor at a speed proportionalto the angular velocity of the motor driven roll, means for variablyreducing the voltage generated by said roll speed generator, means forsetting said voltage reducing means to reduce the roll speed generatorvoltage in direct proportion to the diameter of a fresh roll comprisingan arm connected to said Voltage reducing means and disposed in the pathof roll movement by said reel to the roll accelerating position, andmeans responsive to an excess of web speed generator voltage over rollspeed generator voltage as reduced by said voltage reducing means forsupplying to said motor an amount of operating energy proportional tosuch excess.

l0. Web roll accelerating apparatus comprising the combination with webconsuming apparatus and a web running thereto, of a fresh web rollsupport, a direct current motor having an armature, a series field and ashunt field, connected to drive a roll on said support, a brush arm foreffecting a splice between the running web and the web of a roll on saidsupport and movable between an operative position and an inoperativeposition, means for initiating movement of said brush arm from itsoperative position toward its inoperative position, means for connectinga source of operating energy to the armature and serieseld of saidmotor, a shunt field energizing circuit, a variable resistor selectivelyconnectible in said shunt field energizing circuit, a dynamic brakingresistor, means responsive to operation of said brush arm movementinitiating means for disconnecting said source of operating energy fromsaid motor armature and said series field and connecting said dynamicbraking resistor thereto and simultaneously connecting said variableresistor in said shunt eld energizing circuit, and means forprogressively reducing the value of said variable resistor as said brusharm moves from its operative to its inoperative position.

11. Web roll accelerating apparatus comprising the combination with Webconsuming apparatus and a Web running thereto, of a fresh web 18 rollsupport, a direct current motor having an armature, a series iield and ashunt field, connected to drive a roll on said support, a web speedgenerator driven by said web consuming apparatus, a roll speed generatordriven by said motor, a brush arm for eecting a splice between therunning web and the web of a roll on said support and movable between anoperative position and an inoperative position, means for initiatingmovement of said brush arm from its operative position toward itsinoperative position, means for connecting a source of operating energyto the armature and series field of said motor, a shunt eld energizingcircuit, a variable resistor selectively connectible in said shunt eldenergizing circuit, a dynamic braking resistor, means responsive to anexcess of roll speed generator voltage over web speed generator voltagefor connecting said dynamic braking resistor to said motor armature andseries eld, means responsive to operation of said brush arm movementinitiating means for disconnecting said source of operating energy fromsaid motor armature and series eld, connecting said dynamic brakingresistor thereto and connecting said variable resistor in said shuntfield energizing circuit, and means for progressively reducing the valueof said variable resistor as said brush arm moves from its operative toits inoperative position.

PAUL L. TOLLISON.

REFERENCES CETED The following references are of record in the le ofthis patent:

UNITED VSTATES PATENTS Number Name Date 1,973,363 Wood Sept. 11, 19342,018,842 Durham Oct. '29, 1935 2,029,045 Wood Jan. 28, 1936 2,039,471Wood May 5, 1936 2,148,094 Wood Feb. 21, 1939 2,237,985 Garman Apr. 8,1941 2,298,877 Edwards et al Oct. 13, 1942 FOREIGN PATENTS NumberCountry Date 413,278 Great Britain July 10, 1934

